This invention relates generally to printing control methods in which a media moves relative to a print source, and more particularly, to a method for controlling a drive shaft of a media roller.
For desktop printers, such as inkjet printers, a media sheet is picked from an input tray and moved along a media path into a print zone where characters, symbols or graphics are printed onto the media sheet. For scanning-type inkjet printers, the media sheet is fed incrementally as a printhead scans across the media sheet. Typically, the media sheet is moved by a linefeed distance between or during printing to a given line.
The media handling system for an inkjet printer includes a set of rollers which move a media sheet along a media path. The rollers are driven by a drive shaft, which in is driven by a drive motor. In many instances there is intermediary gearing for varying the motion of the rollers. A print controller controls the drive motor.
For printing from a desktop computer, a user typically issues a print command within an application program environment. A file specified by the user then is downloaded to the printer for printing. Typically a printer driver handles the communication interface between the computer and the printer. For text printing a conventional print driver issues linefeed commands within a stream of character data so that the character data is printed in a desired visual format, (e.g., with desired margins and desired line spacing). The print controller controls timing for printing characters that achieve the desired format. Such timing is determined by the print driver commands, the data stream and fixed parameters. The fixed parameters are based upon a given physical configuration of a printer. Linefeed distance typically is based upon one or more of these fixed parameters for text, graphic and imaging processing. For example, for text printing the line spacing (e.g., 1, 1.5 or 2) is based upon the fixed linefeed parameter. This invention is directed to a method for adjusting the linefeed distance.